US7382283B2 - Method and device for detecting an overstepping of design loads of the tailplane of an aircraft - Google Patents

Method and device for detecting an overstepping of design loads of the tailplane of an aircraft Download PDF

Info

Publication number
US7382283B2
US7382283B2 US11/146,105 US14610505A US7382283B2 US 7382283 B2 US7382283 B2 US 7382283B2 US 14610505 A US14610505 A US 14610505A US 7382283 B2 US7382283 B2 US 7382283B2
Authority
US
United States
Prior art keywords
aircraft
tailplane
current
safety envelope
coefficients
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active, expires
Application number
US11/146,105
Other versions
US20080097728A1 (en
Inventor
Franck Delaplace
Sylvie Marquier
Gérard Mathieu
Gennaro Squeglia
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Airbus Operations SAS
Original Assignee
Airbus Operations SAS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Airbus Operations SAS filed Critical Airbus Operations SAS
Assigned to AIRBUS FRANCE reassignment AIRBUS FRANCE ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: FRANCK DELAPLACE, MARQUIER, SYLVIE, MATHIEU, GERARD, SQUEGLIA, GENNARO
Publication of US20080097728A1 publication Critical patent/US20080097728A1/en
Application granted granted Critical
Publication of US7382283B2 publication Critical patent/US7382283B2/en
Assigned to AIRBUS OPERATIONS SAS reassignment AIRBUS OPERATIONS SAS MERGER (SEE DOCUMENT FOR DETAILS). Assignors: AIRBUS FRANCE
Active legal-status Critical Current
Adjusted expiration legal-status Critical

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B64—AIRCRAFT; AVIATION; COSMONAUTICS
    • B64D—EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
    • B64D43/00—Arrangements or adaptations of instruments
    • B64D43/02—Arrangements or adaptations of instruments for indicating aircraft speed or stalling conditions
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B64—AIRCRAFT; AVIATION; COSMONAUTICS
    • B64F—GROUND OR AIRCRAFT-CARRIER-DECK INSTALLATIONS SPECIALLY ADAPTED FOR USE IN CONNECTION WITH AIRCRAFT; DESIGNING, MANUFACTURING, ASSEMBLING, CLEANING, MAINTAINING OR REPAIRING AIRCRAFT, NOT OTHERWISE PROVIDED FOR; HANDLING, TRANSPORTING, TESTING OR INSPECTING AIRCRAFT COMPONENTS, NOT OTHERWISE PROVIDED FOR
    • B64F5/00—Designing, manufacturing, assembling, cleaning, maintaining or repairing aircraft, not otherwise provided for; Handling, transporting, testing or inspecting aircraft components, not otherwise provided for
    • B64F5/60—Testing or inspecting aircraft components or systems

Definitions

  • the present invention relates to a method and device for detecting an overstepping of design loads of the tailplane of an aircraft.
  • design loads is understood to mean, within the context of the present invention, the maximum loads that can be supported by the structural parts taken into account (namely the tailplane) without permanent deformations appearing.
  • An inspection of structural parts of the aircraft is generally triggered following the generation by an incident detection computer, for example of the FWC (“Flight Warning Computer”) type, of a speed overshoot alarm (also known as an “overspeed warning”).
  • an incident detection computer for example of the FWC (“Flight Warning Computer”) type, of a speed overshoot alarm (also known as an “overspeed warning”).
  • Such an alarm is tripped when an overshoot of more than four knots of a permitted maximum speed (Mach number) dependent on the current configuration of the aircraft, is detected.
  • the various maximum speeds are determined by virtue of load models specific to each zone of the aircraft, in such a way that the constituent elements of the aircraft do not undergo any structural load of such a kind as to damage them.
  • This operation compels the airline, in accordance with the maintenance manual, to perform a maintenance check of the aircraft. This operation is aimed at verifying the ability of the structure of the aircraft to properly withstand the loads encountered during the speed excursion (Mach number) beyond the flight domain.
  • This check consists in visually ascertaining that cracks/fissures have not developed and/or that structural elements or ties are not deformed and in verifying that the various systems potentially affected are still operating normally.
  • An object of the present invention is to remedy these drawbacks.
  • It relates to a method for detecting on an aircraft, in a particularly effective and reliable manner, any overstepping of design loads of the tailplane of said aircraft, while avoiding inspections of said tailplane that are not visibly justified from a technical point of view.
  • a structural inspection has to be implemented when a pair of current bending and twisting moments lies outside said first safety envelope.
  • said first safety envelope is determined with the aid of load models of the aircraft.
  • said coefficients A1, B1, C1, D1, E1, F1, G1, H1 and I1 depend on the dynamic pressure, on the mass distribution (quantity of fuel, number of passengers, etc.), on the Mach number of the aircraft and on longitudinal aerodynamic characteristics of the aircraft.
  • said coefficients G1 and H1 are zero. These coefficients G1 and H1 may in fact be neglected, and they are used only when a refined calculation of the current bending moment Mx is desired.
  • said coefficients A2, B2, C2, D2, E2, F2, G2, H2 and I2 likewise depend on the dynamic pressure, on the mass distribution (quantity of fuel, number of passengers, etc.), on the Mach number of the aircraft and on longitudinal aerodynamic characteristics of the aircraft.
  • said coefficients G2 and H2 are zero. These coefficients G2 and H2 may in fact be neglected, and they are used only when a refined calculation of the current twisting moment My is desired.
  • the latter embodiment makes it possible in particular to confirm an inspection, requested following the detection of an overstepping of loads with the aid of said first safety envelope (monitoring of the bending and twisting moments).
  • the latter embodiment is implemented, preferably, only when the first aforesaid comparison concludes that an overstepping of loads has occurred.
  • it may however also be implemented (continuously) in parallel with the joint monitoring of the bending moment and of the twisting moment.
  • the present invention also relates to a device for detecting an overstepping of design loads of a tailplane of an aircraft.
  • said device is noteworthy in that it comprises:
  • the device in accordance with the invention moreover comprises seventh means intended to indicate to an operator, as appropriate, that an inspection of the tailplane has to be performed.
  • FIGURE is the schematic diagram of a device in accordance with the invention.
  • the device 1 in accordance with the invention and represented diagrammatically in FIG. 1 is intended to detect on an aircraft (not represented), in particular a transport plane, an overstepping of design loads of the tailplane.
  • said device 1 comprises, according to the invention:
  • Said means 3 , 5 , 7 and 10 which are for example grouped into a computation unit UC implement the aforesaid computations automatically and repetitively, in the course of a flight of the aircraft.
  • Said coefficients A1, B1, C1, D1, E1, F1, G1, H1 and I1 depend on the dynamic pressure, on the mass distribution (quantity of fuel, number of passengers, etc.), on the Mach number of the aircraft and on longitudinal aerodynamic characteristics (effectiveness of control surface, effect of nonlinearity, coupling of tailplane and fin, etc.) of the aircraft. These coefficients may be recorded, for example in the form of tables, in said means 3 .
  • said coefficients G1 and H1 are zero. These coefficients G1 and H1 may in fact be neglected. Preferably, they are used only when a refined calculation of the current bending moment Mx is desired.
  • coefficients A1 to I1 depend on the dynamic pressure, on the mass distribution (quantity of fuel, number of passengers, etc.), on the Mach number of the aircraft and on longitudinal aerodynamic characteristics (effectiveness of control surface, effect of nonlinearity, coupling of tailplane and fin, etc.) of the aircraft.
  • the coefficients G2 and H2 are zero. These coefficients G2 and H2 may in fact be neglected, and they are used only when a refined calculation of the current bending moment My is desired.
  • the device 1 in accordance with the invention also comprises means 12 which are connected by a link 13 to said means 10 and which are intended to indicate to an operator, for example a maintenance operator or a pilot of the aircraft, as appropriate, that an inspection of the tailplane has to be performed.
  • These means 12 may in particular comprise means of display making it possible to display on a display screen 14 the aforesaid indications. They may also comprise means of printing and/or means of alarm, for example, of audible type and/or of visual type, which are in particular mounted in the flight control deck of the aircraft.
  • Such an alarm may be recorded in a maintenance logger, so that the maintenance teams are aware of the progress of the flight and know which maintenance operation(s) they have to perform. Moreover, it is possible to prewarn the maintenance teams in advance so that they are ready to intervene as soon as the aircraft lands.
  • coefficients A1 to I1 depend on the dynamic pressure, on the mass distribution (quantity of fuel, number of passengers, etc.), on the Mach number of the aircraft and on longitudinal aerodynamic characteristics (effectiveness of control surface, effect of nonlinearity, coupling of tailplane and fin, etc.) of the aircraft.
  • the coefficients G3 and H3 are zero. These coefficients G3 and H3 may in fact be neglected. Preferably, they are used only when a refined calculation of the current shearing stress Tz is desired.
  • the latter embodiment makes it possible in particular to confirm an inspection, requested following the detection of an overstepping of loads with the aid of said first safety envelope E 1 (bending and twisting moments).
  • the latter embodiment is implemented, preferably, only when the comparison implemented by the means 17 concludes that an overstepping of loads has occurred.
  • the latter embodiment may however also be implemented in parallel with the joint monitoring of the bending moment Mx and of the twisting moment My.

Landscapes

  • Engineering & Computer Science (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Transportation (AREA)
  • Testing Of Devices, Machine Parts, Or Other Structures Thereof (AREA)
  • Force Measurement Appropriate To Specific Purposes (AREA)
  • Regulating Braking Force (AREA)
  • Emergency Alarm Devices (AREA)
  • Maintenance And Inspection Apparatuses For Elevators (AREA)
  • Traffic Control Systems (AREA)
  • Paper (AREA)

Abstract

Detection of the overstepping of design loads of an aircraft tailplane may include determining current bending and twisting moments applied to the aircraft. The determined bending and twisting moments are compared with a safety envelope to determine the risk of developing permanent deformations on the tailplane. A determination is made as to whether a structural inspection of the tailplane should be performed based on the comparison result.

Description

FIELD OF THE INVENTION
The present invention relates to a method and device for detecting an overstepping of design loads of the tailplane of an aircraft.
BACKGROUND OF THE RELATED ART
The expression design loads is understood to mean, within the context of the present invention, the maximum loads that can be supported by the structural parts taken into account (namely the tailplane) without permanent deformations appearing.
With the obvious aim of safety, an inspection of the tailplane of the aircraft, as well as the repair of any flaws, have to be performed as soon as said design loads are overstepped.
An inspection of structural parts of the aircraft is generally triggered following the generation by an incident detection computer, for example of the FWC (“Flight Warning Computer”) type, of a speed overshoot alarm (also known as an “overspeed warning”).
In general, such an alarm is tripped when an overshoot of more than four knots of a permitted maximum speed (Mach number) dependent on the current configuration of the aircraft, is detected.
The various maximum speeds (Mach numbers) are determined by virtue of load models specific to each zone of the aircraft, in such a way that the constituent elements of the aircraft do not undergo any structural load of such a kind as to damage them.
Such an overshoot of maximum speed (Mach number) may occur upon unusual maneuvers, upon encountering significant turbulence or upon erroneous actions on the part of the pilot.
The activation of this alarm compels the airline, in accordance with the maintenance manual, to perform a maintenance check of the aircraft. This operation is aimed at verifying the ability of the structure of the aircraft to properly withstand the loads encountered during the speed excursion (Mach number) beyond the flight domain.
This check consists in visually ascertaining that cracks/fissures have not developed and/or that structural elements or ties are not deformed and in verifying that the various systems potentially affected are still operating normally.
Such maintenance checks therefore keep the aircraft grounded, which of course penalizes the airline.
Moreover, statistical information originating from airlines points to a relatively significant frequency of occurrence of speed overshoot. In fact, for more round trips, airlines often ask their pilots to fly at speeds close to the maximum speeds. In consequence, a simple gust of wind or turbulence triggers the alarm, thereby compelling the airline to perform the maintenance check as described in the aircraft's maintenance manual.
Now, it is apparent that, in a very large majority of cases, no damage at the level of the structure of the aircraft of crack, fissure, etc. type has been observed. Thus, it is apparent that the criterion compelling or otherwise the carrying out of a maintenance check following a speed overshoot alarm of the aforesaid type, is excessive and unsuited to the requirement.
SUMMARY OF THE INVENTION
An object of the present invention is to remedy these drawbacks.
It relates to a method for detecting on an aircraft, in a particularly effective and reliable manner, any overstepping of design loads of the tailplane of said aircraft, while avoiding inspections of said tailplane that are not visibly justified from a technical point of view.
For this purpose, according to the invention, said method is noteworthy in that:
  • A/ in a preliminary step, a first safety envelope is determined representing a chart formed in a plane on the basis of pairs of values of bending moment and of twisting moment of the tailplane and defined so that, for any pair of such values which lies outside said first safety envelope and which is applied to the aircraft, there exists a risk of appearance of permanent deformations on the tailplane;
  • B/ in the course of a flight of the aircraft, the following steps are carried out repetitively and automatically:
    • a) the current bending moment is estimated;
    • b) the current twisting moment is estimated;
    • c) a first comparison is carried out by comparing the pair formed by said current bending moment and said current twisting moment with said first safety envelope; and
    • d) one determines whether a structural inspection of said tailplane has to be performed, at least on the basis of the result of said first comparison.
A structural inspection has to be implemented when a pair of current bending and twisting moments lies outside said first safety envelope.
Thus, by virtue of the simultaneous monitoring of the bending moment and of the twisting moment of the tailplane, by way of said first safety envelope, a refined evaluation of the load level to which said tailplane has been subjected is obtained. This makes it possible to significantly reduce the number of inspections (or maintenance checks) to be triggered relating to said tailplane and hence the drawbacks stemming therefrom.
Moreover, by virtue of the taking into account of said first safety envelope:
    • the monitoring is particularly effective and simplified, since said first safety envelope is formed on the ground before the flight; and
    • the evaluation of a possible overstepping of loads is very refined, since one does not in general simply take into account a single maximum value for the bending moment and a single maximum value for the twisting moment, but a high number of pairs of bending moment and of twisting moment. It may however happen for certain aircraft that only the maximum value for the bending moment and the maximum value for the twisting moment are monitored.
Preferably, in preliminary step A/, said first safety envelope is determined with the aid of load models of the aircraft.
In a particular embodiment, in step B/a), the current bending moment Mx is determined with the aid of the following expression:
Mx=·A1·α+B1·δqd+C1·δqg+D1·ih+E1·nz·X+F1·nz+G1·q 2 +H1·dq/dt+I1
in which:
    • A1, B1, C1, D1, E1, F1, G1, H1 and I1 are coefficients;
    • α is the angle of incidence of the aircraft, at the level of the tailplane;
    • δqd and δqg are the angles of swing of elevators, right and left, of the aircraft;
    • ih represents the angle of deflection of the tailplane, defined with respect to the axis of the fuselage of the aircraft;
    • nz is the vertical load factor, measured at the center of gravity of the aircraft;
    • X represents the sum of the mass of the tailplane and of the mass of fuel;
    • q is the pitch rate;
    • dq/dt represents the pitch acceleration corresponding to the derivative with respect to time t of the pitch rate q.
In this case, advantageously, said coefficients A1, B1, C1, D1, E1, F1, G1, H1 and I1 depend on the dynamic pressure, on the mass distribution (quantity of fuel, number of passengers, etc.), on the Mach number of the aircraft and on longitudinal aerodynamic characteristics of the aircraft.
In a simplified embodiment, said coefficients G1 and H1 are zero. These coefficients G1 and H1 may in fact be neglected, and they are used only when a refined calculation of the current bending moment Mx is desired.
Furthermore, in a preferred embodiment, in step B/b), the current twisting moment My is determined with the aid of the following expression:
My=A2·α+B2·δqd+C2·δqg+D2·ih+E2·nz·X+F2·nz+G2·q 2 +H2·dq/dt+I2
in which, in addition to the aforesaid parameters, A2, B2, C2, D2, E2, F2, G2, H2 and I2 are coefficients.
Advantageously, said coefficients A2, B2, C2, D2, E2, F2, G2, H2 and I2 likewise depend on the dynamic pressure, on the mass distribution (quantity of fuel, number of passengers, etc.), on the Mach number of the aircraft and on longitudinal aerodynamic characteristics of the aircraft.
In a simplified embodiment, said coefficients G2 and H2 are zero. These coefficients G2 and H2 may in fact be neglected, and they are used only when a refined calculation of the current twisting moment My is desired.
Furthermore, advantageously, we determine:
    • the angles δqd and δqg, on the basis of corresponding deflection orders;
    • the vertical load factor nz and the pitch rate q, on the basis of appropriate measurements;
    • the other abovementioned parameters used, such as ih, q, etc., likewise on the basis of appropriate measurements.
Moreover, in a particular embodiment:
    • in preliminary step A/, a second safety envelope is moreover determined representing a chart formed in a plane on the basis of pairs of values of twisting moment and of shearing stress of the tailplane and defined so that, for any pair of such values which lies outside said second safety envelope and which is applied to the aircraft, there exists a risk of appearance of permanent deformations on the tailplane; and
    • in the course of the flight of the aircraft, the following steps are carried out automatically:
      • a current shearing stress is estimated;
      • a second comparison is carried out by comparing the pair formed by said current twisting moment and said current shearing stress with said second safety envelope; and
      • in step d), one determines whether a structural inspection of said tailplane has to be performed, likewise on the basis of the result of said second comparison.
The latter embodiment makes it possible in particular to confirm an inspection, requested following the detection of an overstepping of loads with the aid of said first safety envelope (monitoring of the bending and twisting moments). In such a case, the latter embodiment is implemented, preferably, only when the first aforesaid comparison concludes that an overstepping of loads has occurred. Naturally, it may however also be implemented (continuously) in parallel with the joint monitoring of the bending moment and of the twisting moment.
Advantageously, said current shearing stress Tz is determined with the aid of the following expression:
Tz=A3·αB3·δqd+C3·δqg+D3·ih+E3·nz·X+F3·nz+G3·q 2 +H3·dq/dt+I3
in which, in addition to the aforesaid parameters, A3 to I3 are coefficients.
The present invention also relates to a device for detecting an overstepping of design loads of a tailplane of an aircraft.
According to the invention, said device is noteworthy in that it comprises:
    • a set of information sources;
    • first means for determining, with the aid of information emanating from said set of information sources, a current bending moment;
    • second means for determining, with the aid of information emanating from said set of information sources, a current twisting moment;
    • third means for carrying out a first comparison, by comparing the pair formed by said current bending moment and said current twisting moment with a first safety envelope representing a chart formed in a plane on the basis of pairs of values of bending moment and of twisting moment of the tailplane and defined so that, for any pair of such values which lies outside said first safety envelope and which is applied to the aircraft, there exists a risk of appearance of permanent deformations on the tailplane; and
    • fourth means for determining whether a structural inspection of said tailplane has to be performed, at least on the basis of said first comparison.
In a particular embodiment:
    • said device furthermore comprises:
      • fifth means for determining, with the aid of information emanating from said set of information sources, a current shearing stress; and
      • sixth means for carrying out a second comparison, by comparing the pair formed by said current twisting moment and said current shearing stress with a second safety envelope; and
    • said fourth means determine whether a structural inspection of said tailplane has to be performed, likewise on the basis of the result of said second comparison.
Furthermore, advantageously, the device in accordance with the invention moreover comprises seventh means intended to indicate to an operator, as appropriate, that an inspection of the tailplane has to be performed.
BRIEF DESCRIPTION OF THE DRAWING
The single FIGURE of the appended drawing will elucidate the manner in which the invention may be embodied. This FIGURE is the schematic diagram of a device in accordance with the invention.
 DETAILED DESCRIPTION OF THE INVENTION
The device 1 in accordance with the invention and represented diagrammatically in FIG. 1 is intended to detect on an aircraft (not represented), in particular a transport plane, an overstepping of design loads of the tailplane.
For this purpose, said device 1 comprises, according to the invention:
    • a set 2 of information sources, specified hereinbelow;
    • means 3 which are connected by a link 4 to the set 2 of information sources, to determine in the course of a flight of the aircraft a current bending moment Mx;
    • means 5 which are connected by a link 6 to the set 2 of information sources, to determine in the course of the flight of the aircraft a current twisting moment My;
    • means 7 which are connected by links 8 and 9 respectively to said means 3 and 5, to carry out a comparison, namely to compare the pair C1 formed by said current bending moment Mx and said current twisting moment My with a first safety envelope E1
      • is determined on the ground, for example during mission preparation;
      • represents a chart formed in a plane on the basis of pairs of values of bending moment and of twisting moment of the tailplane;
      • is defined so that, for any pair (of such values of bending moment and of twisting moment) which lies outside said first safety envelope E1 and which is applied to the aircraft, there exists a risk of appearance of permanent deformations on the tailplane;
      • is determined with the aid of standard load models of the aircraft; and
      • is, for example, recorded in said means 7; and
    • means 10 which are connected by a link 11 to said means 7, to determine whether a structural inspection of said tailplane has to be performed, at least on the basis of the result of the comparison carried out by said means 7.
Said means 3, 5, 7 and 10 which are for example grouped into a computation unit UC implement the aforesaid computations automatically and repetitively, in the course of a flight of the aircraft.
In a preferred embodiment, said means 3 determine said current bending moment Mx, with the aid of the following expression:
Mx=A1·α+B1·δqd+C1·δqg+D1·ih+E1·nz·X+F1·nz+G1·q 2 +H1·dq/dt+I1
in which:
    • A1, B1, C1, D1, E1, F1, G1, H1 and I1 are coefficients;
    • α is the angle of incidence of the aircraft, at the level of the tailplane;
    • δqd and δqg are the angles of swing of elevators, right and left, of the aircraft;
    • ih represents the angle of deflection of the tailplane, defined with respect to the axis of the fuselage of the aircraft;
    • nz is the vertical load factor, measured at the center of gravity of the aircraft;
    • X represents the sum of the mass of the tailplane and of the mass of fuel;
    • q is the pitch rate;
    • dq/dt represents the pitch acceleration corresponding to the derivative with respect to time t of the pitch rate q.
Said coefficients A1, B1, C1, D1, E1, F1, G1, H1 and I1 depend on the dynamic pressure, on the mass distribution (quantity of fuel, number of passengers, etc.), on the Mach number of the aircraft and on longitudinal aerodynamic characteristics (effectiveness of control surface, effect of nonlinearity, coupling of tailplane and fin, etc.) of the aircraft. These coefficients may be recorded, for example in the form of tables, in said means 3.
In a simplified embodiment, said coefficients G1 and H1 are zero. These coefficients G1 and H1 may in fact be neglected. Preferably, they are used only when a refined calculation of the current bending moment Mx is desired.
Moreover, by virtue of said set 2 of information sources, we determine:
    • the angles δqd and δqg, on the basis of corresponding deflection orders;
    • the vertical load factor-nz and the pitch rate q, on the basis of appropriate measurements;
    • the other abovementioned parameters used, such as ih, q, etc., likewise on the basis of appropriate measurements.
Moreover, said means 5 determine the current twisting moment My with the aid of the following expression:
My=A2·α+B2·δqd+C2·δqg+D2·ih+E2·nz·X+F2·nz+G2·q 2 +H2·dq/dt+I2
in which A2, B2, C2, D2, E2, F2, G2, H2 and I2 are coefficients.
Just like the coefficients A1 to I1, said coefficients A2 to I2 depend on the dynamic pressure, on the mass distribution (quantity of fuel, number of passengers, etc.), on the Mach number of the aircraft and on longitudinal aerodynamic characteristics (effectiveness of control surface, effect of nonlinearity, coupling of tailplane and fin, etc.) of the aircraft.
In a simplified embodiment, the coefficients G2 and H2 are zero. These coefficients G2 and H2 may in fact be neglected, and they are used only when a refined calculation of the current bending moment My is desired.
Thus, by virtue of the simultaneously monitoring of the bending moment Mx and of the twisting moment My of the tailplane (by way of said first safety envelope E1), which is implemented by the device 1 in accordance with the invention, a refined evaluation of the load level to which said tailplane has been subjected is obtained.
This makes it possible to significantly reduce the number of inspections (or maintenance checks) to be triggered relating to said tailplane and hence the drawbacks stemming therefrom.
Moreover, by virtue of the taking into account of said safety envelope E1:
    • the monitoring is particularly effective and simplified, since said first safety envelope E1 is formed on the ground before the flight; and
    • the evaluation of a possible overstepping of loads is very refined, since one does not in general simply take into account a single maximum value for the bending moment and a single maximum value for the twisting moment, but a high number of pairs of bending moment and of twisting moment (which define said first safety envelope E1).
The device 1 in accordance with the invention also comprises means 12 which are connected by a link 13 to said means 10 and which are intended to indicate to an operator, for example a maintenance operator or a pilot of the aircraft, as appropriate, that an inspection of the tailplane has to be performed. These means 12 may in particular comprise means of display making it possible to display on a display screen 14 the aforesaid indications. They may also comprise means of printing and/or means of alarm, for example, of audible type and/or of visual type, which are in particular mounted in the flight control deck of the aircraft.
It will be noted that such an alarm may be recorded in a maintenance logger, so that the maintenance teams are aware of the progress of the flight and know which maintenance operation(s) they have to perform. Moreover, it is possible to prewarn the maintenance teams in advance so that they are ready to intervene as soon as the aircraft lands.
Additionally, in a particular embodiment:
    • said device 1 moreover comprises:
      • means 15 which are connected by a link 16 to said set 2 of information sources, to determine a current shearing stress Tz; and
      • means 17 which are connected by links 18 and 19 respectively to said means 5 and 15, to carry out a comparison, namely to compare the pair C2 formed by said current twisting moment My and said current shearing stress Tz with a second safety envelope E2. This second safety envelope E2 (not represented):
        • is likewise determined on the ground, for example during mission preparation;
        • represents a chart formed in a plane on the basis of pairs of values of twisting moment and of shearing stress of the tailplane;
        • is defined so that, for any pair (of such values of twisting moment and of shearing stress) which lies outside said second safety envelope E2 and which is applied to the aircraft, there exists a risk of appearance of permanent deformation on the tailplane;
        • is determined with the aid of standard load models of the aircraft; and
        • is, for example, recorded in said means 17; and
    • said means 10 which are connected by a link 20 to said means 17, determine whether a structural inspection of said tailplane has to be performed, likewise on the basis of the result of the comparison carried out by said means 17.
In a particular embodiment, said means 15 determine said current shearing stress Tz with the aid of the following expression:
Tz=A3·α+B3·δqd+C3·δqg+D3·ih+E3·nz·X+F3·nz+G3·q 2 +H3·dq/dt+I3
in which A3, B3, C3, D3, E3, F3, G3, H3 and I3 are coefficients.
Just like the coefficients A1 to I1, said coefficients A3 to I3 depend on the dynamic pressure, on the mass distribution (quantity of fuel, number of passengers, etc.), on the Mach number of the aircraft and on longitudinal aerodynamic characteristics (effectiveness of control surface, effect of nonlinearity, coupling of tailplane and fin, etc.) of the aircraft.
In a simplified embodiment, the coefficients G3 and H3 are zero. These coefficients G3 and H3 may in fact be neglected. Preferably, they are used only when a refined calculation of the current shearing stress Tz is desired.
The latter embodiment makes it possible in particular to confirm an inspection, requested following the detection of an overstepping of loads with the aid of said first safety envelope E1 (bending and twisting moments). In such a case, the latter embodiment is implemented, preferably, only when the comparison implemented by the means 17 concludes that an overstepping of loads has occurred. Naturally, the latter embodiment may however also be implemented in parallel with the joint monitoring of the bending moment Mx and of the twisting moment My.

Claims (14)

1. A method for detecting an overstepping of design loads of the tailplane of an aircraft, said method comprising:
A/ determining, in a preliminary step, a first safety envelope representing a chart formed in a plane on the basis of pairs of values of bending moment and of twisting moment of the tailplane and defined so that, for any pair of such values which lies outside said first safety envelope and which is applied to the aircraft, there exists a risk of permanent deformations developing on the tailplane;
B/ carrying out, in the course of a flight of the aircraft, the following steps repetitively and automatically:
a) estimating the current bending moment;
b) estimating the current twisting moment;
c) carrying out a first comparison by comparing said current bending moment and said current twisting moment with said first safety envelope; and
d) determining whether a structural inspection of said tailplane has to be performed, at least on the basis of the result of said first comparison.
2. The method as claimed in claim 1, wherein in step d), an alarm is emitted in the flight control deck of the aircraft, if a structural inspection of said tailplane has to be performed.
3. The method as claimed in claim 1, wherein in preliminary step A/, said first safety envelope is determined with the aid of load models of the aircraft.
4. The method as claimed in claim 1, wherein in step B/a), said current bending moment Mx is determined with the aid of the following expression:
Mx=·A1·α+·B1·δqd+C1·δqg+D1·ih+E1·nz·X+F1·nz+G1·q2+H1·dq/dt+I1 in which:
A1, B1, C1, D1, E1, F1, G1, H1 and I1 are coefficients;
α is the angle of incidence of the aircraft, at the level of the tailplane;
δqd and δqg are the angles of swing of elevators, right and left, of the aircraft;
ih represents the angle of deflection of the tailplane, defined with respect to the axis of the fuselage of the aircraft;
nz is the vertical load factor, measured at the center of gravity of the aircraft;
X represents the sum of the mass of the tailplane and of the mass of fuel;
q is the pitch rate;
dq/dt represents the pitch acceleration corresponding to the derivative with respect to time t of the pitch rate q.
5. The method as claimed in claim 4, wherein said coefficients A1, B1, C1, D1, E1, F1, G1, H1 and I1 depend on the dynamic pressure, on the mass distribution, on the Mach number of the aircraft and on longitudinal aerodynamic characteristics of the aircraft.
6. The method as claimed in claim 4, wherein said coefficients G1 and H1 are zero.
7. The method as claimed in claim 1, wherein in step B/b), said current twisting moment My is determined with the aid of the following expression:
My=A2·α+B2·δqd+C2·δqg+D2·ih+E2·nz·X+F2·nz+G2·q2+H2·dq/dt+I2 in which:
A2, B2, C2, D2, E2, F2, G2, H2 and I2 are coefficients;
α is the angle of incidence of the aircraft, at the level of the tailplane;
δqd and δqg are the angles of swing of elevators, right and left, of the aircraft;
ih represents the angle of deflection of the tailplane, defined with respect to the axis of the fuselage of the aircraft;
nz is the vertical load factor, measured at the center of gravity of the aircraft;
X represents the sum of the mass of the tailplane and of the mass of fuel;
q is the pitch rate;
dq/dt represents the pitch acceleration corresponding to the derivative with respect to time t of the pitch rate q.
8. The method as claimed in claim 7, wherein said coefficients A2, B2, C2, D2, E2, F2, G2, H2 and I2 depend on the dynamic pressure, on the mass distribution, on the Mach number of the aircraft and on longitudinal aerodynamic characteristics of the aircraft.
9. The method as claimed in claim 7, wherein said coefficients G2 and H2 are zero.
10. The method as claimed in claim 1, further comprising:
determining, in preliminary step A/, a second safety envelope representing a chart formed in a plane on the basis of pairs of values of twisting moment and of shearing stress of the tailplane and defined so that, for any pair of such values which lies outside said second safety envelope and which is applied to the aircraft, there exists a risk of permanent deformations developing on the tailplane; and
carrying out, in the course of the flight of the aircraft, the following steps automatically:
estimating a current shearing stress;
carrying out a second comparison by comparing said current twisting moment and said current shearing stress with said second safety envelope; and
in step d), determining whether a structural inspection of said tailplane has to be performed, likewise on the basis of the result of said second comparison.
11. The method as claimed in claim 10, wherein said current shearing stress Tz is determined with the aid of the following expression:
Tz=A3·α+B3·δqd+C3·δqg+D3·ih+E3·nz·X+F3·nz+G3·q2+H3·dq/dt+I3 in which:
A3, B3, C3, D3, E3, F3, G3, H3 and I3 are coefficients;
α is the angle of incidence of the aircraft, at the level of the tailplane;
δqd and δqg are the angles of swing of elevators, right and left, of the aircraft;
ih represents the angle of deflection of the tailplane, defined with respect to the axis of the fuselage of the aircraft;
nz is the vertical load factor, measured at the center of gravity of the aircraft;
X represents the sum of the mass of the tailplane and of the mass of fuel;
q is the pitch rate;
dq/dt represents the pitch acceleration corresponding to the derivative with respect to time t of the pitch rate q.
12. A device for detecting an overstepping of design loads of a tailplane of an aircraft, which device comprises:
a set of information sources;
a first section for determining, with the aid of information emanating from said set of information sources, a current bending moment;
a second section for determining, with the aid of information emanating from said set of information sources, a current twisting moment;
a third section for carrying out a first comparison, by comparing said current bending moment and said current twisting moment with a first safety envelope representing a chart formed in a plane on the basis of pairs of values of bending moment and of twisting moment of the tailplane and defined so that, for any pair of such values which lies outside said first safety envelope and which is applied to the aircraft, there exists a risk of permanent deformations developing on the tailplane; and
a fourth section for determining whether a structural inspection of said tailplane has to be performed, at least on the basis of said first comparison.
13. The device as claimed in claim 12, wherein:
said device furthermore comprises:
a fifth section for determining, with the aid of information emanating from said set of information sources, a current shearing stress; and
a sixth section for carrying out a second comparison, by comparing said current twisting moment and said current shearing stress with a second safety envelope; and
said fourth section determines whether a structural inspection of said tailplane has to be performed, likewise on the basis of the result of said second comparison.
14. The device as claimed in claim 12, which furthermore comprises a seventh section intended to indicate to an operator, as appropriate, that an inspection of the tailplane has to be performed.
US11/146,105 2004-06-15 2005-06-07 Method and device for detecting an overstepping of design loads of the tailplane of an aircraft Active 2026-02-04 US7382283B2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR0406455 2004-06-15
FR0406455A FR2871439B1 (en) 2004-06-15 2004-06-15 METHOD AND APPARATUS FOR DETECTING EXCEEDING OF SIZING LOADS OF THE REAR HORIZONTAL EMPUMING OF AN AIRCRAFT

Publications (2)

Publication Number Publication Date
US20080097728A1 US20080097728A1 (en) 2008-04-24
US7382283B2 true US7382283B2 (en) 2008-06-03

Family

ID=34942371

Family Applications (1)

Application Number Title Priority Date Filing Date
US11/146,105 Active 2026-02-04 US7382283B2 (en) 2004-06-15 2005-06-07 Method and device for detecting an overstepping of design loads of the tailplane of an aircraft

Country Status (6)

Country Link
US (1) US7382283B2 (en)
EP (1) EP1607814B1 (en)
AT (1) ATE380362T1 (en)
CA (1) CA2509428C (en)
DE (1) DE602005003612T2 (en)
FR (1) FR2871439B1 (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090292409A1 (en) * 2006-09-14 2009-11-26 The Boeing Company Responding to aircraft excursions from flight envelopes
US20100312497A1 (en) * 2009-06-03 2010-12-09 Airbus Operations (Sas) Method and device for determining critical buffeting loads on a structure of an aircraft
US20110202291A1 (en) * 2010-02-12 2011-08-18 Honeywell International Inc. Aircraft dynamic pressure estimation system and method
US8629788B1 (en) * 2010-08-10 2014-01-14 Rockwell Collins, Inc. Sensing, display, and dissemination of detected turbulence
US10228692B2 (en) 2017-03-27 2019-03-12 Gulfstream Aerospace Corporation Aircraft flight envelope protection and recovery autopilot

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2912991B1 (en) * 2007-02-28 2009-12-04 Airbus France METHOD AND DEVICE FOR DYNAMICALLY REDUCING CHARGES GENERATED ON AN AIRCRAFT.
US9771171B1 (en) * 2016-03-09 2017-09-26 Rosemount Aerospace Inc. Aircraft wing deformation monitoring and analysis system
JP6803352B2 (en) * 2018-03-15 2020-12-23 株式会社Ｓｕｂａｒｕ Flight restriction setting system, flight restriction setting method and flight restriction setting program
CN110576981B (en) * 2019-08-19 2024-04-30 沈阳宝通门业有限公司 Inclination-adjustable vertical tail dock working platform
CN113704876B (en) * 2021-08-05 2023-06-02 中国航空工业集团公司沈阳飞机设计研究所 3D combined screening method for airfoil load

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4302745A (en) 1980-01-10 1981-11-24 The United States Of America As Represented By The Secretary Of The Air Force Aircraft load factor overload warning system
GB2192723A (en) 1986-06-21 1988-01-20 Messerschmitt Boelkow Blohm Operational-load monitoring system for aircraft
US5359326A (en) 1993-03-16 1994-10-25 The United States Of America As Represented By The Administrator Of National Aeronautics And Space Administration Aircraft maneuver envelope warning system

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4302745A (en) 1980-01-10 1981-11-24 The United States Of America As Represented By The Secretary Of The Air Force Aircraft load factor overload warning system
GB2192723A (en) 1986-06-21 1988-01-20 Messerschmitt Boelkow Blohm Operational-load monitoring system for aircraft
US5359326A (en) 1993-03-16 1994-10-25 The United States Of America As Represented By The Administrator Of National Aeronautics And Space Administration Aircraft maneuver envelope warning system

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090292409A1 (en) * 2006-09-14 2009-11-26 The Boeing Company Responding to aircraft excursions from flight envelopes
US7636618B2 (en) * 2006-09-14 2009-12-22 The Boeing Company Responding to aircraft excursions from flight envelopes
US20100312497A1 (en) * 2009-06-03 2010-12-09 Airbus Operations (Sas) Method and device for determining critical buffeting loads on a structure of an aircraft
US8255174B2 (en) * 2009-06-03 2012-08-28 Airbus Operations (Sas) Method and device for determining critical buffeting loads on a structure of an aircraft
US20110202291A1 (en) * 2010-02-12 2011-08-18 Honeywell International Inc. Aircraft dynamic pressure estimation system and method
US8374804B2 (en) 2010-02-12 2013-02-12 Honeywell International Inc. Aircraft dynamic pressure estimation system and method
US8629788B1 (en) * 2010-08-10 2014-01-14 Rockwell Collins, Inc. Sensing, display, and dissemination of detected turbulence
US10228692B2 (en) 2017-03-27 2019-03-12 Gulfstream Aerospace Corporation Aircraft flight envelope protection and recovery autopilot
US10930164B2 (en) 2017-03-27 2021-02-23 Gulfstream Aerospace Corporation Aircraft flight envelope protection and recovery autopilot
US11580865B2 (en) 2017-03-27 2023-02-14 Gulfstream Aerospace Corporation Aircraft flight envelope protection and recovery autopilot
US12033526B2 (en) 2017-03-27 2024-07-09 Gulfstream Aerospace Corporation Aircraft flight envelope protection and recovery autopilot

Also Published As

Publication number Publication date
CA2509428C (en) 2012-05-15
FR2871439B1 (en) 2006-09-08
EP1607814B1 (en) 2007-12-05
FR2871439A1 (en) 2005-12-16
US20080097728A1 (en) 2008-04-24
DE602005003612D1 (en) 2008-01-17
DE602005003612T2 (en) 2008-11-13
EP1607814A1 (en) 2005-12-21
CA2509428A1 (en) 2005-12-15
ATE380362T1 (en) 2007-12-15

Similar Documents

Publication Publication Date Title
EP2092401B1 (en) Hard landing detection
US7382283B2 (en) Method and device for detecting an overstepping of design loads of the tailplane of an aircraft
CN108382384A (en) Fault detect based on brake torque and temperature
US7636618B2 (en) Responding to aircraft excursions from flight envelopes
CN113837639B (en) A risk assessment system for aircraft encountering wake turbulence based on multi-dimensional indicators
US7271741B2 (en) Method and device for detecting an overstepping of design loads of the fin of an aircraft
US9250152B2 (en) Method and device for calibrating load sensors
KR102075538B1 (en) Method of individual aircraft tracking based on actual operational flight data
US7617023B2 (en) Process and device for monitoring the validity of a speed cue of an aircraft and system for generating a speed cue comprising such a device
JPS5830899A (en) Valueing system for safety of aircraft structure
US7164366B2 (en) Process and device for detecting on an aircraft an overshoot of design loads at the level of a structural part of said aircraft
Shahani et al. Damage tolerance approach for analyzing a helicopter main rotor blade
US20220214244A1 (en) Systems and methods for assessing structural health
Nelson The trailing vortex wake hazard: Beyond the takeoff and landing corridors
EP4137412A1 (en) Ice detector system and method
Weber et al. Recent experiences of helicopter main rotor blade damage
Zhang et al. The Design of Static Test Scheme for Composite Aileron Structure of Large Aircraft
Venugopal et al. Damage Tolerance Assessment Towards Structure Integrity For C-130 Aircrafts Of Royal Malaysian Air Force
Meng et al. Research and application of wing load behavior in stall flight test
Cai Research on flight test method and risk control of civil aircraft with maximum practicable rate for rotation
Bolds-Moorehead et al. Ground Minimum Control Speed (VMCG) Testing of Transport Aircraft
Lei Aircraft Composite Structure Static Strength Airworthiness Verification Technology
Patel et al. F/A-22 vertical tail buffet strength certification
CN116923713A (en) An aircraft landing data monitoring method and system
Phillips Technology Innovations for Aircraft'Hard Landing'Events.

Legal Events

Date Code Title Description
AS Assignment

Owner name: AIRBUS FRANCE, FRANCE

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:FRANCK DELAPLACE;MARQUIER, SYLVIE;MATHIEU, GERARD;AND OTHERS;REEL/FRAME:016675/0443

Effective date: 20050221

FEPP Fee payment procedure

Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

STCF Information on status: patent grant

Free format text: PATENTED CASE

AS Assignment

Owner name: AIRBUS OPERATIONS SAS, FRANCE

Free format text: MERGER;ASSIGNOR:AIRBUS FRANCE;REEL/FRAME:026298/0269

Effective date: 20090630

FPAY Fee payment

Year of fee payment: 4

FPAY Fee payment

Year of fee payment: 8

MAFP Maintenance fee payment

Free format text: PAYMENT OF MAINTENANCE FEE, 12TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1553); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

Year of fee payment: 12